How to run a cron job as a specific user?

I have a couple of commands I want executed after the machine boots up. A user shouldn't have to log in or anything for them to run.

I found this great answer suggesting crontab with the @reboot keyword, however this will run as root, and I'd like to run as a specific user created for these "services" (not actual system services).

What are someways to achieve that same effect with any given user?

You could create a crontab for the specific user like so:

crontab -u <username> -e

Or more simply, you could just run crontab -e when logged in as that user.

Alternatively, you could prefix your command in your (root) crontab with sudo -u <username> to run the command as the specified user.